1. Field of the Invention
The present invention relates to a method of treating the surface of a substrate for a liquid crystal display device.
2. Description of The Related Art
FIG. 3 shows a conventional method for treating the surface of a substrate for a liquid crystal display device as disclosed in Japanese Published Patent Application 63-96630. As shown in FIG. 3, finely pulverized ice particles 7 are ejected by a blast nozzle 2 onto a film disposed on a glass substrate 5 for orienting a liquid crystal material. This glass substrate 5 is secured to a table 6 in a cabinet 4 having an exhaust duct 3. Under high pressure, the blast nozzle 2 ejects the ice particles 7 with the aid of a high-pressure gas 1 which is compressed air or high-pressure nitrogen. The ice particles 7 thus ejected are received by a hopper 8 and are again supplied to the blast nozzle 2.
Treatment of the surface of a substrate for a liquid crystal display device in accordance with the conventional method is performed as described above by pulverizing a large block of ice to form small ice particles. Formation and pulverization of a large block of ice is inefficient and leads to the following problems. When a machine is provided to pulverize the ice, this machine must be kept cool, increasing costs. Furthermore, it is very difficult to obtain, by means of mechanical pulverization, ice particles of uniform diameter. In addition, during pulverization, dust is mixed with the ice particles.